After absorbing the 7th and final blast core the next mission is "The Final Decision" which is the last in the game. Cole will start up the RFI only to find out its true purpose before being stopped by Zeke. This is the final choice which decides which ending you play through. You're two female companions switch sides at the end, so siding with Nix and agreeing to power up and use the RFI is the Good Karma Choice and siding with Kup and agreeing to help the beast is the Evil Karma Choice.

This trophy will pop if you side with Kuo for the Evil Karma choice, it will pop after the credits once you are placed into free roam mode.

There have been reports that this trophy does not unlock properly if you skip the ending credits. If that happens, simply beat the game again (you'll be taken back prior to making your last decision end game) and sit through the credits this time and it should unlock.

No, you must have two different saves. You could try going to the last level with good karma and make another save, then on that save go on a killing spree and go evil. I am assuming you can have just one evil karma point and still get this trophy, but I have never tried.

yeah, might be tough to get full evil karma by doing that. might as well just play it twice. on my good playthrough now doing everything i can, then the evil play through on hard will be a blast. just kill everything in sight!

ok here's my idea for a third game cole's now the beast and you're going around killing the army and recruiting conduit's killing millions of pepole and at the end of the game you find out that Zeke is not dead and that he was not dead just in a coma like state and he is now a conduit and you swich from playing as Cole to Zeke (cotroles simeler to cole's) and try to kill the beast what do you think?